1. Field of the Invention
This invention relates to exhaust vent systems, and more particularly to exhaust vent systems for clothes dryers having connections for attaching duct components to the dryer and to a vent opening in a wall.
2. Description of the Prior Art
Dryer exhaust conduits conduct substantial quantities of heated air and some lint from the dryer to an external location. Because of the amount of thermal energy involved in the vented air and in the dryer itself, dryer hose installation must be carefully made. Preferably, all-metal exhaust conduits are used throughout the dryer duct system. The conduits are usually solid wall construction or helical corrugation known as xe2x80x9cflexxe2x80x9d conduit, and have a large diameter opening on one end and a smaller diameter opening on another end, such that multiple conduits may be attached together through a telescopic fit. The conduits are generally secured together by use of a band clamp, which may have a tendency to crush the conduit.
One method of connection of multiple conduits is disclosed in U.S. Pat. No. 5,819,435, having the same assignee as the instant invention. In this method, each length of conduit has male and female opposing ends in the form of sleeves that are adapted to overlap, with a frictional fit, obviating the need for a clamp and avoiding crushing of the conduit. The method further includes a universal elbow connector normally having a female rotatable fitting on one end and a male rotatable fitting on the other end, each for receiving a duct component.
In most residential installations, the dryer is located against an exterior wall and the dryer exhaust is vented through the exterior wall to the atmosphere. Oftentimes, the dryer is located in a basement or other below-grade portion of the house. Since the dryer vent outlet is typically located near the bottom of the dryer a conduit is run from the bottom of the dryer to an above-grade portion of the exterior wall. An elbow is commonly used to redirect the dryer exhaust upwardly from the dryer bottom. The conduit connects the elbow to the exterior vent.
In any telescopic connection, it is preferred that no edges or other sharp surfaces inside the conduits face the direction of air flow so as to avoid the collection of lint along the edge or surface. Lint collection and retention within the conduit can restrict the flow of air through the conduit, which can degrade the performance of the dryer, and create a potential fuel source in the event of a dryer fire.
The conduits used in either of the prior art methods require connection, at one end, to the vent outlet of the dryer being vented, and at the other end to an exterior exhaust vent which allows air to pass from the room wherein the dryer is located. While the interface built into the dryer has become standardized in the industry, presenting a predictable connection to the manufacturer and installer of the dryer venting, the interface of the exhaust vent, often built into the house, however, has been found to vary by region and by builder, and cannot be relied upon to be of a uniform dimension. This results in the manufacturer having to manufacture connectors of multiple sizes, requiring additional inventory management, or in the alternative, restricting itself out of those markets. The installer is required to carry connectors of differing sizes, also creating a storage and inventory management problem.
It would be advantageous to provide a single product that would be adaptable to connect flexible dryer duct of a given size with exhaust vents of slightly differing configurations or sizes. It would be desirable that such a product would not require additional adapters, thereby avoiding the waste of at least one adapter from every product package. It would be desirable that the product would not require excessive modification by the installer, thereby avoiding a loss of productivity. It is also desirable that the connection not have any surfaces that face the exhaust air flow direction to deter the accumulation of lint.
The invention relates to an elbow for use in a dryer duct assembly comprising at least one component for connecting a dryer vent outlet and an exhaust vent. The component has an inlet and outlet. The dryer vent outlet and one of the component inlet and outlet have a standardized diameter. The elbow comprises a body defining an interior flow passage for permitting the passing of dryer exhaust air through the body. A first end of the body terminates in a first edge to define an inlet opening to the interior flow passage. A second end of the body terminates in a second edge to define an outlet opening to the interior flow passage. At least a portion of the first end has an effective inner diameter greater than the standardized diameter for receiving therein one of the dryer vent outlet and component inlet or outlet with the standardized diameter, and at least a portion of the second end has an effective outer diameter less than the standardized diameter for being received within the other of the dryer vent opening and component inlet or outlet with the standardized diameter.
In another aspect, the invention relates to a dryer duct assembly for connecting a dryer vent outlet with a standardized diameter and an exhaust vent. The dryer duct assembly comprises a duct and an elbow. The duct having an inlet and an outlet, with both the duct inlet and outlet having a diameter equal to the standardized diameter. The elbow comprises a hollow body defining an interior flow passage for permitting the passing therethrough of dryer exhaust air, the body having an inlet opening and an outlet opening. The inlet opening has an effective diameter nominally greater than the standardized diameter for insertion of the dryer vent outlet therein and the outlet opening has an effective diameter nominally less than the standardized diameter for being slidably received within the duct inlet.